Each "it" catalog can have a background image, selecting other images in the catalog will display them over the top of the image in a non-destructive way. To set up and use this feature do the following:

  1. View your background image a click the background toggle/indicator. The indicator will turn blue as will the icon next to the image in the catalog.

2. Now view your foreground image. If you image has alpha, as Mr Ray does below it will be composited on top of you background. 

 

Using The Wipe Tool

When you are using a background image you can also use the "wipe tool" to reveal parts of the background under the foreground.

  1. Click the "wipe tool" mode.

2. left-drag the mouse in the image view to see under the foreground.

 

3. The direction of the wipe can toggle from vertical to horizontal by click the wipe direction button